The present invention pertains to a die mold for the manufacture of crate like containers, particularly of bottle transport crates, which mold includes a generally rectangular base plate with cores jutting up at the corners, an inner core which can be moved back and forth in relation to the base plate, and four lateral wedges which can be moved back and forth at a relatively sharp angle to the vertical when the mold is closed and opened.
In using modern storage and transport procedures, increasingly higher requirements have been placed on the stability and load capacity of bottle crates in recent years. In the construction of crates, the basic guiding principle must be that in stacking several pallets on top of one another, a load of up to 1,000 kg. may be exerted on the bottom crates. This necessitates a corresponding stability of the lateral walls of the crates. On the other hand, the actual weight of such synthetic crates must not be too great, since otherwise the material requirements would be excessive, and the manufacturing costs would increase beyond proper proportion.
In the known types of synthetic bottle crates, indentations are provided, as a rule, in the lateral walls in such a manner that on the top end there appears a wall section which can be simultaneously used as a grasping handle. Serrations running vertical to the lateral walls are provided in the lateral walls for reinforcement. The manufacture of these serrations does not provide any difficulty.
For the further increase of load capacity, bottle crates have been developed in which the corners are formed from a hollow profile. In this fashion, however, only a partial improvement in stability is produced, because the wall areas existing between the corners constitute a simple profile, as before. In order to manufacture crates of this type, die molds are used which contain a base plate on whose corners cores constituting the hollow profile jut up. The lateral edging of the mold is formed by means of four lateral wedges which are provided with projecting pieces which extend toward the interior and which serve to produce the indentations or cut-outs in the lateral walls. Into the outer mold there juts from the top a core which has on its bottom side projections and grooves, which, in accordance with the specific structure of the base plate, produce a corresponding formation of the crate base, which is, for the most part, intermittent in structure. In constructing die molds of this type, measures must be provided which permit a damage proof and substantially automatic removal of the crates from the molding implement. In order to open the mold following termination of the mold injection procedure, the inner core of the mold is moved away from the base plate, whereby the finally processed crate remains on the inner core. Synchronously, the lateral wedges are opened by being moved outwardly at a sharp angle to the base plate on the inner inclinations of supporting wedges. During this joint movement of the lateral wedges and the core, the lateral wedges, including the projections provided at the ends of the lateral wedges, are moved outwardly so that when the lifting motion of the lateral wedges is terminated, the container can be removed from the core by a stripping device without any interference.